On simultaneous arithmetic progressions on elliptic curves

In this paper we study elliptic curves which have a number of points whose coordinates are in arithmetic progression. We first motivate this diophantine problem, prove some results, provide a number of interesting examples and, finally point out open questions which focus on the most interesting aspects of the problem for us.Comment: 22 page

Les ocupacions de la cova de Sant Llorenç (Sitges, Garraf) : Noves aportacions al coneixement de la prehistòria del Garraf

Els treballs arqueològics fets a la cova de Sant Llorenç des del 2007 han permès documentar l'ús esporàdic, però dilatat de la cavitat al llarg de la prehistòria i amb diferents finalitats. Les evidències referents a l'ús sepulcral de la cova de Sant Llorenç resulten força interessants per la novetat que representen i per la complexitat i variabilitat que sembla que devien tenir les pràctiques funeràries d'aquestes comunitats al llarg del III mil·lenni

On the ubiquity of trivial torsion on elliptic curves

The purpose of this paper is to give a "down--to--earth" proof of the well--known fact that a randomly chosen elliptic curve over the rationals is most likely to have trivial torsion

Estudiantes universitarios ante los retos formativos de las redes sociales : el caso de Colombia

Este artículo analiza los retos formativos de estudiantes universitarios colombianos de Ciencias de la Comunicación con el objetivo de diagnosticar su uso de las redes sociales. Se han realizado encuestas a 71 estudiantes y 12 grupos focales. Los resultados muestran que los estudiantes analizados utilizan las redes sociales como herramientas complejas que les que les permiten formarse, participar, informarse, cooperar, trabajar y entretenerse. Los estudiantes demuestran un alto nivel crítico y de conocimiento de las ventajas y desventajas de las redes. Las conclusiones muestran que las redes sociales son un reto formativo para las nuevas generaciones de estudiantes de Comunicación ya que su practicidad, inmediatez y eficacia, las convierten en una fuente periodística prioritaria, que debe ser también tenida en cuenta por los formadores de los futuros periodistas.This article analyses the formative challenges of Colombian University Students from the Faculty of Communication Studies. The principal aim of this research is to identify their use of the social networks. Seventyone surveys and 12 focus groups were carried out. The results show that students in the sample use the social networks as complex tools that allow them to train, inform, participate, cooperate, work and entertain themselves. The students demonstrate a high critical level and an important knowledge of the advantage and disadvantages of the networks. The conclusions demonstrate that social networks are a formative challenge for the new generations of Communication students. Their effectiveness, immediacy and efficiency make them a fundamental journalistic source that needs to be taken into account by faculty of future journalists

Characterization of the Use of Emergency Contraception from Sentinel Pharmacies in a Region of Southern Europe

Numerous studies have been published suggesting that emergency contraception (EC) is used repeatedly, but a lack of information regarding the profile of users makes it difficult to evaluate actual consumer habits. The aim of this study was to obtain information regarding the profile of users who obtain EC and other factors that might play a role, and to provide criteria to evaluate and improve the strategies of current contraceptive programs. This was an observational one-year study based on surveillance data on the provision of EC to women of reproductive age in 60 community pharmacies in Catalonia, Spain. In total, 941 notifications of dispensation of EC in Catalonia were received. A total of 44.2% of users said it was not the first time that they had taken the medication (repeat user). The percentage of users who used condoms was lower in repeat users compared to first-time users (56.7% vs. 64.4%, p < 0.05). A total of 25.7% of users stated that they did not use any barrier contraceptive method. The use of natural methods in repeat users was 53.8% in the subgroup who requested the medication after 48 h, significantly higher than in users who obtained the medication within the first 24 h (p < 0.05). A high percentage of repeat users with risky sexual behaviors were detected, suggesting that new measures must be implemented to provide information for this method, together with educational and preventive strategies

Long-term calcium imaging reveals functional development in hiPSC-derived cultures comparable to human but not rat primary cultures

Models for human brain-oriented research are often established on primary cultures from rodents, which fails to recapitulate cellular specificity and molecular cues of the human brain. Here we investigated whether neuronal cultures derived from human induced pluripotent stem cells (hiPSCs) feature key advantages compared with rodent primary cultures. Using calcium fluorescence imaging, we tracked spontaneous neuronal activity in hiPSC-derived, human, and rat primary cultures and compared their dynamic and functional behavior as they matured.We observed that hiPSC-derived cultures progressively changed upon development, exhibiting gradually richer activity patterns and functional traits. By contrast, rat primary cultures were locked in the same dynamic state since activity onset. Human primary cultures exhibited features in between hiPSC-derived and rat primary cultures, although traits from the former predominated. Our study demonstrates that hiPSC-derived cultures are excellent models to investigate development in neuronal assemblies, a hallmark for applications that monitor alterations caused by damage or neurodegeneration

Hyaluronic acid-based bioink improves the differentiation and network formation of neural progenitor cells

Introduction: Three-dimensional (3D) bioprinting is a promising technique for the development of neuronal in vitro models because it controls the deposition of materials and cells. Finding a biomaterial that supports neural differentiation in vitro while ensuring compatibility with the technique of 3D bioprinting of a self-standing construct is a challenge. Methods: In this study, gelatin methacryloyl (GelMA), methacrylated alginate (AlgMA), and hyaluronic acid (HA) were examined by exploiting their biocompatibility and tunable mechanical properties to resemble the extracellular matrix (ECM) and to create a suitable material for printing neural progenitor cells (NPCs), supporting their long-term differentiation. NPCs were printed and differentiated for up to 15 days, and cell viability and neuronal differentiation markers were assessed throughout the culture. Results and Discussion: This composite biomaterial presented the desired physical properties to mimic the ECM of the brain with high water intake, low stiffness, and slow degradation while allowing the printing of defined structures. The viability rates were maintained at approximately 80% at all time points. However, the levels of β-III tubulin marker increased over time, demonstrating the compatibility of this biomaterial with neuronal cell culture and differentiation. Furthermore, these cells showed increased maturation with corresponding functional properties, which was also demonstrated by the formation of a neuronal network that was observed by recording spontaneous activity via Ca2+ imaging

Influenza syndromic surveillance based on sentinel pharmacies in Catalonia (Spain) in 2017-2020

Objective: To analyse influenza surveillance data obtained from sentinel pharmacies of Catalonia, Spain, in 2017−18, 2018−19 and 2019-20 influenza seasons. Methods: Influenza surveillance information was collected from a representative sample of community pharmacies of Catalonia. Influenza-like cases were identified based on the ECDC criteria.The Chi-square test and Odds ratios were used to compare percentages between different population groups, with a p <0.05 considered as statistically significant. The screening method was used to assess influenza vaccination effectiveness. The moving epidemic method (MEM) was used to assess influenza epidemics in the three influenza seasons. Results: A total of 836, 1,000 and 587 influenza-like cases were reported in 2017−18, 2018−19 and 2019−20. Sentinel pharmacies dispended medications to 94-98% of patients. Paracetamol, cough medication, ibuprofen and antihistamines were dispended to more than 25% of patients. Dispensation of antibiotics decreased by 57% from 2017-18 to 2019-20 (OR = 0.45, 95% CI: 0.28-0.74, p < 0.001). Physicians prescribed medications to 30-38% of influenza-like patients. The influenza vaccination effectiveness in individuals aged 65 or more years was 51.4% (95% CI: 41.9−60.7) in 2018-19 and 67% (95% CI: 53.4−79.8) in 2019-20 influenza seasons. Influenza epidemics occurred from week 50 of 2017 to week 7 of 2018; from week 51 of 2017 to week 8 of 2019; and from week 2 to week 7 of 2020. Conclusion: The influenza surveillance system based on sentinel pharmacies provided consistent information on the influenza epidemic, influenza morbidity not assisted in health centres and medications used to treat influenza-like cases during 2017−2019

Actividades para promover la gestión crítica de la información de Internet aplicadas a estudiantes de farmacia

Con el fin de promover la adquisición de habilidades y destrezas que permitan al estudiante de Farmacia desarrollar una actitud activa y crítica frente a la información disponible en Internet, así como saber seleccionar las fuentes de información de Internet adecuadas para su formación, se ha llevado a cabo un proyecto de innovación docente (2008PID-UB/115) cuyo objetivo final es fomentar la gestión crítica de la información. Para ello se han diseñado una serie de ejercicios integrados en una actividad basada en casos clínicos, que forma parte de la evaluación continuada de la asignatura de Fisiopatología de la Licenciatura de Farmacia (UB). Se ha evaluado el proyecto a través de las calificaciones obtenidas en las actividades y las encuestas de opinión de un total de 379 estudiantes. Los resultados evidencian que la mayoría de estudiantes (90%) valoran muy positivamente las actividades planteadas, considerando que favorecen su aprendizaje y formación personal, y les aportan criterios útiles y provechosos para el análisis y selección de información biomédica a través de Internet. Por último, cabe destacar que el proyecto planteado ha demostrado ser aplicable a un grupo numeroso de estudiantes de Grado y constituye una estrategia válida para fomentar competencias transversales relacionadas con la gestión de la información, de gran relevancia para el futuro profesional farmacéutico